1. Field of the Invention
This invention relates to the resilient art, and, more particularly, to an arrangement providing the resilient resistance to movement provided by torsion in a portion of the arrangement.
2. Description of the Prior Art
In many applications, resilient arrangements for resisting deformation are required. Such resilient arrangements have often been provided by various types of springs such as coil springs, leaf springs, and the like. Additionally, certain types of torsion bar structures have been utilized, for example, in automobile suspensions and the like. However, there has long been a need for a resilient arrangement in which, for a given geometry of the arrangement, the force required to move one portion of the spring toward (or away from, depending on the application) another may be selected over a wide range of relationships. In particular, in certain applications it may be desirable to have this relationship be such that, once a predetermined force is exceeded, one portion of the torsion arrangement will move toward another portion of the torsion arrangement resiliently, without further substantial increase in the force, thus providing a comparatively flat force-deflection relationship. Other arrangements desired may include those wherein the force required additionally decreases until one portion of the torsion arrangement is at a predetermined separation from another portion of the torsion arrangement and then the force increases for further movement of one portion of the torsion arrangement toward the other. The point at which the force commences to increase is generally termed an inflection point and torsion arrangements in which the inflection point may be selected for a given configuration of the torsion arrangement to be at any desired separation between one portion and the other portion of the torsion arrangement, are often desired. Similarly, such arrangements often are desired in which the rate of change of the force-deflection curve may be preselected.
Such resilient arrangements as above described are often desired in such diverse applications as hinges to provide positive opening or closing of the structures to which the hinges are attached; collapsible lifeboats to provide automatic opening thereof without the requirement for a positive air pressure to maintain buoyancy; oil containment booms to provide automatic opening thereof without the requirement of positive pressure to maintain buoyancy; and numerous other applications, for example, cushioning arrangements, shock mounts, or other applications. Thus, the invention described herein may be utilized in any desired application where the characteristics of the particular improved torsion arrangement as described herein may be advantageously utilized. Thus, invention herein is not limited to application to a particular embodiment, but may be generally utilized where desired.